Enhanced Cr(VI) stabilization in soil by carboxymethyl cellulose-stabilized nanosized Fe0 (CMC-nFe0) and mixed anaerobic microorganisms
| Autor: | Penchi Chiang, Mei Su, Jinhua Wu, Ping Li, Weizhao Yin, Li Liu, Zhanqiang Fang, Yili Fang |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Zerovalent iron
Environmental Engineering Environmental remediation Chemistry Microorganism 0208 environmental biotechnology Substrate (chemistry) chemistry.chemical_element 02 engineering and technology General Medicine 010501 environmental sciences Management Monitoring Policy and Law engineering.material Dispersion (geology) 01 natural sciences 020801 environmental engineering Carboxymethyl cellulose Chromium engineering medicine Lepidocrocite Waste Management and Disposal 0105 earth and related environmental sciences medicine.drug Nuclear chemistry |
| Zdroj: | Journal of Environmental Management. 257:109951 |
| ISSN: | 0301-4797 |
| DOI: | 10.1016/j.jenvman.2019.109951 |
| Popis: | A collaborative system of carboxymethyl cellulose stabilized nanosized zero-valent iron (CMC-nFe0) and microorganisms was set up to enhance the stabilization of Cr(VI) in soil. In comparison with an aqueous-bound Cr(VI) removal of 18.9% in the nFe0 system, a higher Cr(VI) removal of 68.9% was achieved in the nFe0 and microorganisms system after 14 d remediation because the microorganisms on the nFe0 surface promoted nFe0 corrosion and enhanced abiotic and biotic Cr(VI) stabilization by generating highly active minerals such as magnetite, lepidocrocite and green rust on the nFe0 surface. As a stabilizing agent for nFe0 and an organic substrate for microorganisms, CMC on the nFe0 surface not only enhanced the dispersion of nFe0, but also boosted the activity of microorganisms, resulting in a promotion of 0.9 and 0.5 times higher aqueous-bound Cr(VI) removal via the improvement of nFe0 and microorganisms respectively, thus a total 4 times higher aqueous-bound Cr(VI) removal of 95.3% was achieved in the CMC-nFe0 and microorganisms system as compared to the nFe0 system. After 14 d remediation, easily available species of Cr(VI) and Crtotal, such as water soluble (WS), exchangeable (EX) and bounded to carbonates (CB), were mainly transformed to less available Fe–Mn oxides-bounded (OX) and residual (RS) species because of the production of ferrochrome precipitates (CrxFe1-xOOH or CrxFe1-x(OH)3). Besides, the stabilization of Cr(VI) in the CMC-nFe0 and microorganisms system was pH-dependent and it increased with CMC-nFe0 dosage. Due to excellent Cr(VI) stabilization and Cr immobilization, coupled CMC-nFe0 and anaerobic microorganisms process is of great potential in remediating Cr(VI)-containing soil. |
| Databáze: | OpenAIRE |
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